Great to read from you again! I just turned your post into a sticky as it's a very essential question.
First; do you have a movie of your piaffe? Because I'm not sure what you mean with having a pause between the diagonals - that's not required in piaffe.
Then about the passage: I guess you mean with suspension getting the horse to become less forward, and more upwards moving.
First of all I would look at what your horse offers naturally: does she canter more or does she trot more? Sjors is a trotter, Blacky prefers canter. So with Sjors I used the trot, and with Blacky the canter to ask for more upwards movement. So SJors now does (did, he forgot it a couple of days ago
) passage, and Blacky tries hard on collected canter and is getting there quite well. Sjors is learning the collected canter from the passage (that's why he got confused and temporarily lost the first), and Blacky is learning that he can move more upwards in canter so that he can later on try the same in trot too.Preparation for passageThe quality of your transitions
The key for getting passage however is in both methods the quality of your upwards and downwards transitions: Does your horse flex at the poll both in walk and trot? And more important: does he maintain this flexion or lowers his head when you ask for an upwards or downwards transition? If he tenses in transitions by bringing his head up and hollowing the back, your horse makes transitions by locking his body - and that will hinder him in making transitions towards passage too. So that should first be solved: if your horse drags his head up- and backwards when making a normal transition, ask him to make these transitions while moving in a small volte while keeping the head bent to the inside. This bending in stretches the outside neck muscles and prevents them from drawing the head up - of course do so on both sides equally! When he understands that he can stay soft during transitions, you can ask him to soften during straight transitions too by asking him to lower his head in the gait you're working in and only when he lowers his head, you ask for the transition - and reward immediately when he responds! So then you have a horse who drops his head and neck when making a rtansition, which is a really good start. only then you can ask him to stay collected with a flexed poll during regular transitions - and of course logically only then you can start to think of doing transitions to passage.Spanish walk
A well-known method from the classical dressage is to teach the passage through or after the Spanish walk. The important thing about the Spanish walk is that it teaches the horse an exaggerated upwards movement in walk - as the passage is in fact a kind of exaggerated upwards trot. The Spanish walk paves the road to this passage because it gives the horse the ideas he needs in order to think of the passage in terms of upwards movement and more leg-action. On the other hand the Spanish walk stretches the shoulders in such a way that it's easier to rotate them more expressively in the passage too.
Some classical dressage teachers also teach their horses the Spanish trot: a Spanish walk in trot. This isn;t the same as the passage as in the Spanish trot the frontleg is lifted higher and more horizontal stretched in the air - and because of that there's less time for the suspension moment in which the horse jumps upwards and loose of the ground. So even though the Spanish trot seems to be much more upwards as the frontlegs stretch forwards, in fact the movement is less upwards than the passage as in the passage the frontlegs don't move that much, but the body jumps up much more. However, some horses learn the passage better after the Spanish trot because in that gait they've learned to slow their trot really down while keeping it expressive. Then they only have to exchange the stretched frontlegs for a higher jump and you've got the passage. Methods:Mimicry
For me the most important too for creating upwards movement, is mimicry: teach your horse that he can mimick your movements, and start doing trot-passage transitions yourself. With a trotpony like SJors that worked very well after a few weeks of mimicking my transitions walk-halt-trot-slow trot-fast trot. One day when Sjors really started to mimick every speed I started and also trotted collected at a slow pace, getting into the improved trot you ask for.
When we got at that point, I started 'collecting' myself more in that gait and did a couple of steps passage myself. Sjors' first response was to brake to a halt and look at me as if I had gone beserk - and I rewarded him for that. At least he was giving me a reaction, and even though it wasn't really flattering, it meant that he had seen that I had changed my gaits. Then he just trotted along for a couple of times while I made transitions to passage (and still looked at me in a very weird way), and then he decided to try it too, and gave one upwards diagonal in trot.
With Blacky, his collected canter is based on mimicry too: I asked him to canter when running together, but at the same time slowed down myself. Blacky tried to match that by instead of going to canter going to walk or trot, and at some point tried if he could do the same in canter too. Bingo!Lungeing
The first step essentially is to teach your horse that if you flick the whip against/under the hindfeet, this isn't a cue for 'go faster' from now on, but instead a cue for 'move more collected'. Every time your horse responds by first slowing down more, then collecting more, you reward him for this. Then when he really understands the fact that it's not about speed anymore, you start to ask for more exaggerated responses to this whip-cue: for a bigger upwards jump in trot or when making a transition towards trot.
The important thing with this method to remember is that it easily can go wrong: because next to teaching your horse the passage this way, you can also annoy him into the passage in this way by continuously flicking the whip, when he responds with speed tell him to slow down, then whipcue etc. That's also a way - but I don't think it's a good way because instead of teaching your horse to enjoy this collected feeling, you teach him to dislike it as the training method used is something he dislikes. So be very careful when trying this method and preferably try it at liberty, with your horse circling around you like in lungeing, but now at liberty. That you you at least give him the chance to say 'Stop being so annoying and rude!' when in your enthusiasm and perfectionism you get demanding and rude with the whipcues. And that's only too easy!
That was my problem when trying this: the pony's weren't offering me the collection, I was nagging them for it. That, and the fact that I constantly had to cue them for collection instead of having them do it themselves led me away from this method and towards trying to do it totally at liberty because that doesn't involve physical cues, and is less intrusive or demanding towards the horse and therefore gives him more space to answer as he wants.
But I remember quite a few people over here having reached the passage already too. What did you use?